[Previous] | [Session 125] | [Next]
J. Racusin, T.A. Mckay, E. Sheldon (University of Michigan), M. Strauss (Princeton University), M. Bernardi (University of Chicago)
Comparisons between virial masses and lensing masses are made for a sample of ~20,000 early-type galaxies from the Sloan Digital Sky Survey (SDSS) spectroscopic survey. Early-type galaxies are strictly selected on photometric and spectroscopic criteria to provide a clean and homogeneous sample of nearby (z < 0.3) galaxies with accurate stellar velocity dispersions. Virial masses are calculated using the stellar spectroscopic velocity dispersions and other Fundamental Plane parameters output by the SDSS pipelines. Lensing masses for subsets defined by viral mass are derived by weak lensing techniques. These two mass estimates characterize the galaxies on substantially different scales. The virial mass measurement apertures are on the order of tens of kpc, whereas the lensing mass apertures are on the order of hundreds of kpc. We conclude by quantifying the strong relationship seen between small scale virial and large scale lensing mass estimates.
The author(s) of this abstract have provided an email address for comments about the abstract: jracusin@umich.edu